1. Field of the Invention
The present invention relates to an improved ski pole having an adjustable length, which said ski pole is provided with two telescopically movable tube sections which are inserted into each other and are arrestable at their respective positions by an arresting means, which said ski pole is provided further with an operating member located at the handle portion of said ski pole and operationable for a mutual arresting or unlatching of both said tube sections, which said operating member is arranged to be reachable by the fingers of the skier's hand gripping the ski pole, which arresting means comprises a latching arrangement having a plurality of catches, and whereby there is provided a spring which engages at the one end the inner tube section and at the other end the outer tube section, which said spring biasses both said tube sections away from each other.
Such a ski pole can be used on the one hand as a rigid ski pole having an adjustable length and on the other hand as a spring elastic ski pole yielding elastically in its longitudinal direction. Such features are specifically of interest for cross-country skiers because at the one hand the length of the ski pole may be adjustable in accordance with the prevailing shape of the country and at the other hand the spring force which is stored in the ski pole may be used as thrusting aid.
2. Description of the Prior Art
Such a ski pole is disclosed in the NO-PS 73 712. The latch of this known ski pole (see FIG. 4) comprises three elastically and radially spreadable tongues, which are operated by the operating member by the agency of an axial bar. The catches are formed by circumferential grooves. The operating member is shaped as a push button. If the push button is not operated, both tube sections are locked or arrested, respectively, against each other whereby a rigid ski pole having the respective chosen length is present. When the push button is pressed, the tube sections are unlatched and an elastically yielding ski pole is achieved. The drawback of this ski pole is that when using such ski pole as elastically yielding ski pole in order to utilize the stored spring force as thrust aid, the push button must continuously be pressed down. A further drawback of this known ski pole is that during the adjustment of the longitudinal extent of the rigid ski pole the latch cannot positively snap and lock into predetermined, for instance, two or three catches when the ski pole has attained a sought length during the skiing, i.e. when engaging the ground.